This paper presents the results of a preliminary study, in which grandchildren/children and grandparents/middle aged to older adults were observed while interacting with each other and with an App, on a tablet, to develop a proposed activity. Before and after these Joint Media Engagement (JME) sessions, participants were also interviewed, in order to collect data and to assess the perceived impact of the JME sessions in the quality of the intergenerational relationship, on the attitude towards each other and on children and older adults’ digital literacy. The main goals of this preliminary study were to validate data collection instruments and techniques, namely the JME sessions activities, Apps and protocols and the pre- and post-JME session interviews’ scripts. This preliminary study is part of a research that aims to understand the interactions and communication processes taking place during JME sessions involving grandparents/older adults (over 55 years old) and grandchildren/children (5 to 10 years old) in collaborative usage of tablets and tablets’ Apps, in order to develop guidelines for designing mobile contents and Apps to support and promote intergenerational interactions.